The overall goal of this project is to elucidate the mechanisms by which activation of the JC virus (JCV) in glial cells of the brain is influenced by HIV-1 infection. JCV is the etiologic agent of the fatal demyelinating disease, progressive multifocal leukoencephalopathy (PML). JCV is normally latent in immunocompetent people, but it is activated in brains of individuals with AIDS. The significantly higher incidence of PML in patients with AIDS than in other immunosuppressive conditions suggests that there may be an interaction between HIV-1 and JCV. A role has been demonstrated for the HIV-1 protein Tat in stimulating JCV late gene transcription and JCV DNA replication. In addition, HIV-1 infection alters pathways of production and signal transduction of immunomodulators, including TGF- (31, in the central nervous system. Thus, we propose to determine how the Smad nuclear effectors of TGF-(31 interact with Tat and its cellular partner proteins Pura and Cyclin TI/Cdk9 at JCV and PCNA promoter sequences. The double chromatin immunoprecipitation method of the Johnson laboratory will be employed in conjunction with functional studies on JCV DNA replication and gene transcription. We shall employ a microarray to identify genes in glial cells regulated by exposure to cytokines produced by HIV-1-infected cells and mass spectrometry to characterize the active-sites of Smad protein interactions. [unreadable] [unreadable] PUBLIC HEALTH RELEVANCE: These results will help to dissect the regulatory pathways that modulate JCV gene expression and regulation in the HIV-1-infected brain, which may lead to the identification of new molecular targets for therapy. [unreadable] [unreadable] [unreadable]